Valve mechanism.



PATENTED AUG. -13, 1907.

R. A. MoKBB. VALVE MECHANISM.

APPLICATION FILED arm. 12. 1900.

3 SHEETS-SHEET 1.

JNVENTOR No. 863,084. PATENTED AUG. 13, 1907. R0 AI VALVE MECHANISM.

APPLICATION FILED SEPT. 12. 1906.

3 SHBETSSHEET 2.

INVENTOR ATTORNET.

(weld/30M.

11.. WASHINGTON. n. c.

-No. 863,084. PATENTED AUG. 13, 1907.

R. A. MoKEE.

VALVE MECHANISM.

APPLIOATION FILED SEPT. 12. 1906.

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pa i INVENTOR I W ATTOIQNET.

UNITED STATES PATENT OFFICE.

ROBERT A. MoKEE, OF MILWAUKEE, WISCONSIN, ASSIGNOR TO ALLISCHALMERSCOMPANY. OF MILWAUKEE, WISCONSIN, A CORPORATION OF NEW JERSEY.

VALVE MECHANISM.

Specification of Letters Patent.

Patented Aug. 13, 1907.

Application filed September 12,1906. Serial No. 334,217.

To all whom it "may concern:

Be it known that I, ROBERT A. MeKnn, a citizen of the United States,residing at Milwaukee, in the county of Milwaukee and State ofWisconsin, have invented a certain new and useful Valve Mechanism, ofwhich the following is a specification.

This invention relates to valve mechanism and especially to the specificcombination of a plurality of puffing valves to be hereinafter describedand the combination of said valves with an elastic fluid engine.

As the work required from an elastic fluid engine is sometimes in excessof the engines normal capacity, it has been proposed to make provisionfor such excess or overload by admitting the motive fluid at fullpressure into a part of the engine where it is ordinarily usedexpansively at a lower pressure.

In reciprocating engines provided with high pressure cylinders to whichsteam is admitted at its normal pressure and low pressure cylinders inwhich the steam is used expansively at a pressure lower than normal, ithas been proposed to take care of an overload by admitting the steam atits normal pressure into the low pressure cylinders also.

In rotary engines, including steam turbines, it has been proposed totake care of an overload by also admitting the steam at its normalpressure into a part of the engine between the main inlet and theexhaust where in the normal operation of the engine it is used at lessthan normal pressure.

In continuous acting or rotary engines, including steam turbines, it isnecessary at normal load to use a continuous and uninterrupted blast ofsteam in order .to realize the full power of the engine economically.When such an engine is running at less than normal loada continuousblast of throttled steam is not as economical as puffs of steam admittedat intervals and at full steam pressure.

This invention comprises the combination with a continuous acting engineso constructed as to use an elastic fluid expansively, such as, forexample, a rotary engine of a main pufiing valve for admitting themotive fluid thereto in puffs at normal pressure when the engine isworking at less than its normal load, said valve being adapted to beretained open so as to admit an uninterrupted blast of fluid at normalpressure when the engine is working at normal load and a second puffingvalve adapted to admit motive fluid in puffs at normal pressure into anexpansion stage of the engine while the main valve is open. A thirdvalve, or more, could also be used by simply extending the sameprinciple, but it has been deemed sufficient to illustrate only twovalves as they fully disclose the principle and operation of thisinvention, the result attained being the complete control of the enginewhen running at under load, normal load or overload, and the mosteconomical working of the engine under either of these three conditionsof load. By controlling the valves by a governor responsive to thespeeds of the engine, the valves are operated automatically to take careof variations of load upon the engine.

This invention further comprises structure of valve mechanism foraccomplishing the results stated above.

By the expression expansion stage as used in this specification is meantany part of an engine in which an elastic fluid is used as a motivefluid by virtue of its tendency to expand, the pressure of scuh fluid insuch part of the engine under normal conditions of operation being lowerthan the initial pressure of the fluid supplied to said engine.

In the accompanying drawings this invention is illustrated as applied toa steam turbine of the wellknown Parsons type, but it is to beunderstood that this illustration is simply for the purpose ofexhibiting one application of the improved valve mechanism described andclaimed in this specification, and is not to be construed as limitingthe application of this valve mechanism to a steam turbine or to a steamturbine of any particular type, except as a particular claim may solimit it.

In the drawings which form a part of this specification and on which thesame reference characters are used to designate the same elements ineach of the several views,Figure 1 represents an elevation of a steamturbine of the Parsons type with this improved mechanism appliedthereto. Fig. 2 represents a vertical section through the steam chestand valve casings of the valve mechanism shown by Fig. 1. Fig. 3 is aperspective in detail of the valve operating mechanism removed from thevalve casings in order to clearly show the structure and relation of theseveral parts of the mechanism. Fig. 4 is a perspective of a detail ofthe governor connection. I

The turbine shown by Fig. 1 comprises a suitable base upon which issupported the turbine including its shaft A, said turbine consisting ofthe admission stage B and the expansion stage C.

D represents the steam chest to which steam is supplied through thesupply pipe E and from which steam is admitted through a port into thepressure stage B of the turbine through the pipe H, the passage of saidsteam being controlled by the valve mechanism F.

The reference character G represents a second valve mechanism whichcontrols the passage of steam from the steam chest D through thethoroughfare of the pipe I and a port into the expansion stage of theturbine C.

The reference character X represents the exhaust passage from theturbine.

The shaft A is provided with a motion-transmitting mechanism such as thepinion K, which is adapted to mesh with a pinion L secured upon theshaft M,

. idly to its seat.

which, through the instrumentality of an eccentric 0 connected with acrank o, is adapted to oscillate the shaft 0, which in turn is adaptedto operate the steam valves of the valve mechanisms F and G.

The reference character I represents an ordinary type of governor whichis adapted to respond to variations of speed of the shaft A eitherimmediately or mediately, (no specific means for effecting this resultbeing shown, as any of the ordinary forms of connection may be adopted).As the balls of this governor J rise and fall due to variations in speedof the shaft A, motion is communicated through the bifurcated lever oryoke P to the shaft N which in turn controls the operation of the steamvalves of the valve mechanisms F and G.

In Figs. 2 and 3 are shown in detail the specific structures of thevalve mechanisms F and G. Referring to Fig. 2 it. will be noticed thatsteam entering through the supply pipe E will pass into the steam chestD and, if the valve f, which serves as an automatic throttle valve, beopen, will pass through the thoroughfare controlled by said valve andwill then pass out to the turbine through the pipe H. If, at the sametime that the valve f is open, the valve 9 is open, the steam can alsopass through the thoroughfare controlled by said latter valve and intothe turbine through the pipe I. The two valve mechanisms F and Gcomprise the following elements, viz., the valve f adapted to close thethoroughfare through the partition d of the steam chest D; avalve-operating rod f secured to said valve; a spring f retained betweena projection on said valveoperating stem and a fixed part of the valvecasing, the function of said spring being to return the valve f rapvidedwith an enlargement or head f which is adapted to be operated upon byarms of the valve-operating mechanism to raise said valve from its seatin a manner which will be described presently. Attached to thevalve-operating stem f is a piston f which is adapted to move in acylinder f 5 in order to prevent the valve slamming on its seat whenclosed by the springf the cylinder and piston forming a dash pot orretarding device, air being admitted to the cylinder beneath the pistonon the up-stroke of the same through the ball valve controlledpassageway f and being forced outwardly therefrom through the screwcontrolled passageway f on the down-stroke of the piston.

The structure of the valve mechanism G is a duplicate of the mechanismjust described, the reference character 9 with correspondingsuperscripts indicating corresponding elements.

As before described, the shaft 0 is adapted to receive an oscillatingmovement resulting from the rotation of the shaft A. This oscillatingmovement is utilized to raise the valves f and g from their seatsagainst the ten sion of the springs f and g in the following manner:Referring to Fig. 3, it will be seen that the shaft 0, which isoscillated by means of the crank 0 and connecting rod 0 which latter isconnected to the eccentric 0 is rigidly secured to the crank arms o 0 0,0 so that these crank arms oscillate with the shaft 0. Sleeved upon theshaft 0 are the movable members P and P, and suitably sleeved uponsupporting mem bers are similar movable members P and P Securedpreferably upon the same supporting member as the member P are themovable crank arms 0 and 0 The valve-operating stem f is pro-' whilesecured upon the same supporting member as the member P are the movablecrank arms 0 o The crank arms 0 and 0 are united by a member S, Whilethe crank arms 0 and 0 are united by a member T; the members S and Tbeing united by the connecting links 0 and 0 The crank members 0 and 0are united by the member R, and the crank members 0 and 0 are united bythe member U, the members R and U being united by the link members 0 and0".

' The members P, P, P and P are each provided with a projection p, p,p-, 12 respectively, and an arm 1), 19 p, 39 respectively, these armsbeing adapted to engage with the enlargements or heads f and g of thevalve-operating stems f and g respectively, in order to lift said valvesfrom their seats.

In order to operate the arms just referred to, means are provided forcontacting with the projections p, p, p", p, in order to cause themembers P, P P, P to oscillate about their respective supports. Themember S is provided with the projecting fingers s, 8 while the member Tis provided with the projecting fingers t, F, the fingers 8 t beingshown as connected by the spiral spring 3 The member R is provided withthe projecting fingers 1", 1' 7' while the member U is provided withcorresponding projecting fingers 1L, 1L2, a; the fingers 1e and 1' beingacted upon respectively by spiral springs, as clearly indicated by r Thepurpose of these springs is to retain certain of the fingers upon thecams with which they are adapted to cooperate. Located upon the shaft 0as a convenient support but movable independently therefrom are the camsa a which are connected by means of the adjustable rods n and n" withthe crank arms n, a rigidly secured to the shaft N, which shaft throughthe medium of the bifurcated lever or yoke P is oscillated by themovements of the governor J. Cams n and n are movably supported upon thesame supports as members P and P respectively, and are connected withcams n and n by adjustable connecting rods n and vi.

The operation of the parts just described is as follows: The turbinebeing in operation, the shaft A is revolving and transmits its motionthrough the pinions K, L, shaft N, eccentric o connecting rod 0 crank o,to the shaft 0 which is not rotated as the result of this movement, butis simply oscillated. The oscillations of shaft 0 are accompanied bysimilar oscillations of the crank arms 0", 0 o 0 secured thereto, andthese crank arms in turn cause similar oscillations of the crank arms 00 0 0, because of the connecting links 0 0 0 and 0 As the crank arms 0and 0 for example, swing to the right (see Fig. 3), the pro jectingfinger 5 engages with the projection p, thereby oscillating said memberP and rocking upward the arm p, which being engaged under the head 9 ofthe valveoperating stem g, lifts said valve from its seat in oppositionto the spring 9 The projecting finger r in a similar manner and at thesame time causes the Valve f to be raised from its seat through similarinstrumentalities, viz., the projection the valve-operating rod f. Onthe reverse oscillation these several parts would return to their normalposition were it not for the fact that these operating elements justenumerated are duplicated while their action is the reverse of thosejust mentioned. For example, while the parts s p, p 9 are returning totheir normal position as the result of the crank arms 0 and 0 swingingto the left, the finger t contacts with the projection p oscillates themember P swinging upwardly the arm p which engages under the head 9 ofthe valve-operating stem g. The projecting finger 15- contacts with theprojection p raises the arm p with the head or projection f in the sameway and at the same time. It will thus be seen that if the partsenumerated were the only parts to control the valves, the valves wouldbe lifted to their extreme open positions by an oscillation of the crankarms 0*, 0", '0, 0 to the right (see Fig. 3), and would be returnedtowards their seats by the springs f and g as the arms p and 10 werelowered as the result of an oscillation of said crank arms to the left.In order that the valves may be returned suddenlyto their seats by theaction of the springsf and 9 means are provided for disengaging theprojecting lingers s, t', T2, 162, from the projection 17, p", 1), prespectively, such means consisting of the cams n n n a which areconnected with the governor, as already described. Each of these cammembers upon which respectively the projecting fingers s, t, T and u areadapted to rest, is provided with a projection, said projections beingof sufiicient height to cause an amplitude of oscillation of the membersS, T, R and U that will move the projecting fingers 8 5 r and 10 out ofthe path of oscillation respectively of the projections p, 19 p, pthereby allowing the valves j and g to be returned to their seats by thespring f and g In the position of the parts as shown by Fig. 3-with thehead f engaging arms p and p and the head 9 engaging arms 19* and p bothvalves f and g would be off their seats to the theoretical lift for thevalves. If new the crank arms 0", 0, 0 and 0 were oscillated to theright (Fig 3), the arms p and p would lift the valves still further fromtheir seats, vizi, to their extreme limit of movement. On the reverseoscillation the valves would return towards their seats by reason of thetension of the springs f and g but would be prevented from moving fasterthan the arms 19* and p by reason of the heads 9 and f engaging withsaid arms. When the position shown by Fig. 3 is reached the heads g andf 3 would be engaged by the arms p and p which would be moving upwardsand the valves would again be moved to their limit of opening withouthaving closed. This additional length of stroke for the valves isprovided so that while they are open and provide the theoretical openingfor the passage of steam they may be kept in motion to prevent anytendency to stick. In the structure as shown the valves are forced openpositively by the movement of the engine but they are closed by thetension of springs and if the valves were to retain fixed positions forany considerable length of time it is possible that the parts wouldbecome so dirty and corroded that the springs could not move them whenrequired to do so. In order that the valves may operate as puffingvalves and return at intervals to their seats, the knock-off cams n, 11.n and n are provided as described above.

The operation of the mechanism is as follows: Cams and n are adjusted bymeans of the adjustable connecting rod a so that the fingers s and twill be disengaged fi'om the projections p and p at correspondingintervals and cams n and n are similarly adjusted to cause thedisengagement of fingers r u and projections p and p The governor ballsare then raised to their highest position and cams rtand n so adjustedby means of the adjustable connecting rod n that either the finger r isdisengaged from the projection p or the finger Lt from the projection 17at the instant the valve starts to open In other words, so that thevalve is not opened at all. The governor balls are then lowered to theposition which they would assume at normal load and for such a positionof the governor balls the projections on the cams n and n will notengage the fingers r or a during the movement of the mechanism. Thegovernor balls are now lowered a trifle and the cams and 11, adjusted bymeans of the adjustable connecting rod n so that either the finger s isdisengaged from the projection p or the finger F from the projection pimmediately after the valve 9 opens. With an under load on the engineand a tendency to higher speed and consequent elevation of the governorballs, the valve y is closed and the valve f is puffing, the duration ofthe puffs depending upon the position of the cams n and n as determinedby the position of the governor balls. Now as additional load is thrownon the engine and the speed lowers and the governor balls drop, theduration of the puffs of the valve f becomes longer and longerthe loadbeing supposed to increase meanwhileuntil finally the cams n and n havebeen moved around so far that the valve f stops pufling, that is, it isno longer released and permitted to r turn to its seat but is retainedopen. 011 a further decrease of speed and consequent lowering of thegovernor balls, valve g will commence to puff and with an increase ofload and lower speed of the engine the duration of its puffs will beincreased.

By means of the apparatus described it is possible to control an engineaccording to the work imposed upon it from the minimum up to andincluding the normal maximum for which the engine is designed, and it isfurther possible in case of an overload to increase the capacity of theengine and still control it while it is overloaded.

The cams w and 10 (Fig. 3) connected by the adjustable connecting rod7112 are connected by the adjustable connecting rod in with a fixed part'u) of the valve casing. These cams are provided so that the valvef maybe kept pulling if it should be considered desirable after the cams nand n have been moved by the governor to such a position that they nolonger cause the fingers r and n to be disengaged from the projections pand The projecting fingers r, s t and 11/ constitute vibrating levers,and the variable fulcrums for said levers are the cams n n" n" and n 7 77 upon which the levers are rocked.

What I claim is:

1. The combination with a continuous acting engine, such, for example,as a rotary engine or turbine, adapted to be actuated by an elasticfluid, said engine being" provided with a -main inlet for an operatingfluid and an exhaust, said engine being also provided with an expansionstage, said expansion stage being provided with an auxiliary inlet foroperating fluid, positively actuated valve mechanism for controllingsaid inlets, a governor responsive to the speeds of the engine forcontrolling said valve mechanism to admit the operating fluid throughsaid main inlet in pufis at under loads and in an uninterrupted blast atnormal and overloads and to admit operating fluid through said secondaryinlet only while an uninterrupted blast of fluid is being admittedthrough said main inlet.

2. The combination with a continuous acting engine, such, for example,as a rotary engine or turbine, adapted to be actuated by an elasticfluid, said engine being pro vided with a main inlet for an operatingfluid and an exhaust, said engine being also provided with an expansionstage, said expansion stage being provided with an auxiliary inlet foroperating fluid, a positively actuated valve for controlling the flow ofthe operating fluid through said main inlet, a second valve forcontrolling the flow of operating fluid through said auxiliary inlet, agovernor responsive to the speeds of the engine for controlling theaction of said valves, said first mentioned valve being adapted to admitthe operating fluid in puffs while the engine is running at under loadsand in an uninterrupted blast when the engine is running at normal andoverloads, said second valve being so arranged that it admits operat ingfluid only while the first mentioned valve is admitting fluid in anuninterrupted blast.

3. The combination with a continuous acting engine, such, for example,as a rotary engine or turbine, adapted to be actuated by an elasticfluid, said engine being provided with a main inlet for an operatingfluid and an ex haust, said engine being also provided with an expansionstage, said expansion stage being provided with an auxviliary inlet foroperating fluid, a positively actuated valve for controlling the flow ofthe operating fluid through said main inlet, a second positivelyactuated valve for control ling the flow of operating fluid through saidauxiliary inlet, a governor responsive to the speeds of the engine forcontrolling the action of said valves, said first mentioned valve beingadapted to admit the operating fluid in putts while the engine isrunning at under-loads and in an uninterrupted blast when the engine isrunning at normal and overloads, said second valve being so arrangedthat it admits operating fluid only while the first mentioned valve isadmitting fluid in an uninterrupted blast.

4. The combination with a continuous acting engine, such, for example,as a rotary engine or turbine, adapted to be actuated by an elasticfluid, said engine being provided with a main inlet for an operatingfluid and an exhaust, said engine being also provided with an expansionstage, said expansion stage being provided with an auxiliary inlet foroperating fluid, valve mechanism for 0on trolling said inlets,mechanical means for operating said valve mechanism in unison with themotion of said engine, and a governor responsive to the speeds of theengine for controlling said valve mechanism to admit the operating fluidthrough said inlets to the engine.

The combination with an engine of a valve for admitting an operatingfluid thereto, means for transmitting motion from said engine to saidvalve to cause said valve to open, a spring adapted to close said valve,and means adapted to permit said valve to be closed intermittently atunder-loads and to cause said valve to be retained open at normal andover loads.

- 6. The combination with a continuous acting engine, such, for example,as a rotary engine or turbine, adapted to be actuated by an elasticfluid, said engine being pro vided with a main inlet for an operatingfluid and an ex haust, said engine being also provided with an expansionstage, said expansion stage being provided with an auxiliary inlet foroperating fluid, a valve for controlling the flow of the operating fluidthrough said inlets, positively actuated mechanism operated in unisonwith the speeds of the engine adapted to move said valve in onedirection, means to move-said valve in the opposite direction, and agovernor responsive to the speeds of the engine to control saidpositively actuated mechanism.

7. The combination with a continuous acting engine, such, for example,as a rotary engine or turbine, adapted to be actuated by an elasticfluid, said engine being provided with a main inlet for an operatingfluid and an exhaust, said engine being also provided with an expansionstage, said expansion stage being provided with an auxiliary inlet foroperating fluid, t'wo valves for controlling the flow of the operatingfluid through said inlets, positively actuated mechanism operating inunison with the speeds of the engine adapted to move said valves in onedirection, means to move said valves in the opposite direction, and agovernor responsive to the speeds of the engine to control saidpositively actuated mechanism.

8. The combination with a continuous acting engine, such, for example,as a rotary engine or turbine, adapted to be actuated by an elasticfluid, said engine being provided with a main inlet for an operatingfluid and an exhaust, said engine being also provided with an expansionstage, said expansion stage being provided with an auxiliary inlet foroperating fluid, a valve for each inlet to control the flow of theoperating fluid therethrough, each of said valves being provided with aheaded stem, arms adapted to engage with said headed stems to raise saidvalves from their seats, springs for returning said valves toward theirseats, means for moving said arms, and a governor responsive to thespeeds of the engine for controlling the action of said means upon saidarms according to the speeds of said engine.

9. The combination with a continuous acting engine, such, for example,as a rotary engine or turbine, adapted to be actuated by an elasticfluid, said engine being provided with a main inlet for an operatingfluid and an exhaust, said engine being also provided with an expansionstage, said expansion stage being provided with an aux iliary inlet foroperating fluid, a valve for each inlet to control the flow of theoperating fluid therethrough, each of said valves being provided with aheaded stem, arms adapted to engage with said headed stems to raise saidvalves from their seats, springs for returning said valves towards theirseats, means for moving said arms, a governor,responsive to thespeeds ofthe engine for controlling the action of said means upon said armsaccording to the speeds of said engine, and means to permit one of saidvalves to be moved towards its seat only to a limited extent.

In testimony whereof, I affix my signature in the presence of twowitnesses.

ROBERT A. MCKEE.

Witnesses:

FRANK E. DENNETT, ARTHUR C. FLonY.

